<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .box{
            color:yellow;
        }
    </style>

    <script src="./react/react.development.js"></script>
    <script src="./react/react-dom.development.js"></script>
    <script src="./react/babel.min.js"></script>
</head>
<body>
<div id="app"></div>
<script type="text/babel">

    //JSX=JS+xml、


    let app = document.querySelector('#app');
    let root = ReactDOM.createRoot(app);

    // JSX中不会渲染的值：false null undefined ''
    let isShow = 0;
    let element = (
        <div>
            {
                isShow !== 0 && 'hello world'
            }
        </div>
    );

    root.render(element);

</script>
</body>
</html>